1. Field of the Invention
This invention relates to improvements in removable closures for top opening padlocks of the type where the padlock opens at the top to allow access for changing a removable locking cylinder or plug, and also in improvements in removably retaining the shackle in the case.
2. Description of the Prior Art
The purpose of all locks, including padlocks, is to provide security, In this connection, it is known to provide padlocks with high security lock cylinders which are removable. One such arrangement is commercially available from Medeco Security Locks, Inc., in Salem, Virginia. It includes an arrangement for interchanging the lock cylinder through a top opening in the padlock body in accordance with prior U.S. Pat. No. 4,063,435, granted Dec. 20, 1977. There are other high security padlocks known in the prior art and available on the market which have a high security locking cylinder removable through the top of the padlock body; e.g., padlocks made by Sargent & Greenleaf, Inc., in accordance with Harry C. Miller's U.S. Pat. No. 3,713,309. Moreover, many prior art padlocks use balls to lock the shackle.
There is need, however, for a device that is easier and more economical to manufacture than that known in the prior art while having the same high security features with regard to removability of the plug from the top of the padlock. This invention provides such a construction.